Flying boat



F. KLEINHENZ FLYING BOAT Aug. 15, 1933.

Filed May 27. 1931 Patented Aug. 15, 1933 UNITED STATES FLYING BOAT Franz Klcinhenz, Berlin-Treptow, Germany Application May 27, 1931, Serial No. 540,304,

I and in Germany June 2, 1930 3 Claims. (Cl. 2442) The constructions offlying boat that are customary today have various disadvantages, which show themselves particularly inthe defective seaworthiness on the open. Up to thepresent five [5 distinct types of flying boat have been tested,

7 namely: I

Only the constructions named under (2) and (5) can be regarded as intrinsically stable flying boats.

The constructions named above all have vari- "ous disadvantages. Even when lateral stumps or special supporting bodies are provided, the possibility of the water washing over them still exists in whichcase the flying boat suffers considerable loss of transverse stability, or may even lose it entirely. The latter is the case, with single floats which are arranged beside a central boat, when one of the lateral floats entirely loses its buoyancy, by leakage-for example. Double flying boats "also have serious disadvantages, which exhibit themselves particularly when trav- .elling across or along the waves.

A central aeroplane body will also in genera be best able to fulfill the conditions of seaworthiness on ahigh sea. v 4 a The objectof the present invention is to provide an intrinsically stable flying boat, which avoids the disadvantages 'of special stability bodies, and the disadvantages of the float aeroplane and double boat. i a

r In order to attain thisaim the boat body is built on special lines. Since in the case of a boat the boat body must also be the hull, these two bodies must have a coherent form and must be connected with one another by suitable transition surfaces. The hull is to be arranged, ac-

cording to its purpose, as nearly as possible in the central axis, while the actual boat, according to its purpose, that is to say, in order to attain the necessary transverse stability, should a be arranged as far as possible away from the central longitudinal axis of the boat.

The lateral floats must be located as faras possible from the central longitudinal axis of the boat, but not more so than is required by its union with the actual flying-boat hull. The connecting surfaces from the laterally arranged floats to the actual central portions of the boat or hull are to be shaped as far as possible according to the requirements of aerodynamics. The problem is also to be so defined that these float surfaces to be arranged laterally are so selected in their contours that a flooding of these bodies or an over-burdening by water when the boat heels over is as far as possible avoided.

The connecting surfacesbetween the actual float surfaces and the central boat body therefore begins in a convex or swelling line, and is continued to the central body in as'stiif a form as possible. A float surface located in the vertical axis of the boat would give little or'no assistance in obtaining metacentric height, so this surface is entirely excluded from the boat body.

The new form based on these considerations consists according to the invention of a central hull or boat body forming a whole, organically and aerodynamically,.with members projecting towards the sides and downwards, the under sur faces of which form the float surfaces, in such a way that between the projecting members a tunnel shaped cavity is left, bounded by the internal surfaces of the convex members and the under surface of the hull or boat body. The superstructure of the flying-boat body therefore takes its origin from the central hull and divides the float surfaces into two float surfaces separated from one another, for the purpose of connecting the actual float bodies mounted uponthe float surfaces in aerodynamic forms with the hull body, so that in the central longitudinal axis of the flying boat, from the vertex of the boat right to the stern or end of the hull, there remains free a tunnel-like space. The distance of the two float bodies from one another is preferably kept somewhat below the usual distance of a two-float flying boat. The space remainingbetween the lateral float-body surfaces is constructed as high aspossible so as not to hinder the discharge of the water. For the purpose of preventing the water from rising on the inner side walls in the tunnel at the start or landing of the flying boat, and to prevent accumulations of water occurring when the water flows in and out, the tunnelshaped space is constructed in its outlines in the form of a slightly curved nozzle. In order to let the water in the tunnel flow away assmoothly as possible the float surfaces are suitably keeled,

.a known manner.

this being done in such a way that the. outer bilges are located higher than the inner ones. There are therefore actually two keels, which, if it were desired to assemble them in one line, represent the middle keel of a bottom keeled out wards towards both sides. 1 The form of boat described above is applicable to flying boats of any size, from single-motor flying boats right to multimotor flying boats, as well as to single-decker (or monoplane) flying boats, one and-a-halfdecker (or sesqui-plane) flying boats, and double-decker or bi-plane flying boats. tral portion of the boat, which in general is pi i erably arranged as high as possible, may'advantageously constitute the accommodation for- The transition spaces to the actual .floatjb'odies'are pref erably to be provided as larger-rooms for the the driver and for the passengers.

accommodation of passengers, while the lower cavities of the lateral floats serve for carrying freightand working loads. For the shapeof the .boat.it ischaracteristic that the two said lateral floats are assembled both in the bow and in the stern inan aerodynamically closed line, thisbeing -.the case both in plan and in elevation. Onthe whole, therefore, the main contour of theboat, according to both sections, forms as far as possible a streamline body. The lateral keels of the two floats extend in a curved line or surface towards the apex of. the bow, and thesurfaces extending obliquely from the stern apex of the two side bodies similarly extend towards the end of the hull. The flying boat carries as usual at its tail end the elevation and steering mechanism. .Tlieflyingmechanism may be constructed as desired and mounted upon the flying-boat body in The invention. is illustrated by way of example in the accompanying drawing, in which :Figure 1 shows a one-and-a half-decker flying boat in sidefelevation. Figure 2 shows a plan of the same, and Figure 3 an end elevation. The hull-like central body'a is located high above the actual floats b. Against this the two floats b bearsnugly in convex surfaces. The transition surfaces between the hullbody andlateral floats are'denoted by 0. These transition surfaces are constructed either as doubly curved or as parabolic surfaces. ,Both surface forms are completely "convex before the transition point to the actual float surfaces, in order that there may be noloss displacement in the event of the boat having a list, The two keel lines of the lateral floats are denoted in Figure l by d. In the plan of the flying boat in Figure 2, the keel lines d are shown extending to the stern. end, opening out somewhat in order to obtain the aforementioned nozzle effect. The broadening of the keellines opening out in the neighborhood of the bow need only be trifling. Til'ie keel linesd, as .Figure'Z shows, are carried atthe bow in a curved line to the'vert'ex of the bow, while in the stern they,

likewise terminate at the end of the hull ina curved line.

. The tunnel-shape of the .cross section of the boat will be recognized from Figure 3. The two keel lines are there denoted by d, while'the crown of the tunnel surface is denoted by e.

The 93 7;

.tudinal section of the central hull body, in which the lower boundary surface at the same time rep resents the tunnel surface, as Figure 1 shows, is of an elongated spindle shape. The side floats, in theircontour as seen in plan, as Figure 2 shows,

extend in the bow towards tha vertex of the bow and in the stern towards the rear end of the hull in such a way that a stream-line body is produced. The transition surfaces from the lateral floats to the vertex of the bow are denoted by i,whilethe transition bodies from the float stern to the end of the hull are denoted by :1. At the vertex of the bow, therefore, the central hull body a. and thetwo actual side floats b -meet at a point, denoted by k. I 1 I In order to aifordthepilot the freest possible view forwards and towardsthe sides, the cockpit is arranged oppositethe'vertex of the bowandig raised somewhat above it. The cockpit is.constructed projecting out of the actual contour of the boat, inorder that the pilot/may without difficulty be able to'see overthe boat in a forward direction, and if possible also in a rearward-31 direction.

The motors arearranged as high up as possible. Similarly also the vertical and lateral steering mechanism is also to be arranged as far as possible above the surface of the water, and on 5 this account is supported upon the upper surface of the rear end of the hull.

1. A flying bo'atcomprising'in combination a main body portion and lateral lower float por- 1 tions united with said mainportion by outwardly and downwardly sloping sides so as to form a common streamlined body of a tunnel shaped cross section, the bottoms of said float portions being shaped in cross section so as to each ascend against the outer side from a keel forming the lower edge and the stern of said tunnel.

2. A flying boat as claimed in claimel, wherein the keels are straight, seen from above, in their portions merging into the water. I

3. A flying boat comprising in combination a main body portion, laterally extending lower float portions united with said main portion by outwardly and downwardly sloping sides so as to form a common streamlined body of tunnel shape, a supporting wing fastened to said body, and propellers with driving means arranged on said wing, the body being free for the reception of loads, the body being divided by floors intos'everal-compartments, an upper compartment in the narrow main body portion being constructed as asitting room, a lower compartment extending through thelargest available space immediately above the tunnel and being constructed as a bed room,:and the float portions being free for dead loads.

FRANZ KLE'I-NHENZ. 

